Heat dissipation substrate

ABSTRACT

A heat dissipation substrate includes a heat sink, a metal base and an elastic structure. The heat sink includes a carrying portion and supporting portions. The supporting portions are parallel to one another and disposed on a lower surface of the carrying portion. The supporting portions are perpendicular to the carrying portion and surround an accommodating space with the carrying portion. The carrying portion has first rough surface structure disposed on a portion of the lower surface and located in the accommodating space. The metal base is disposed below the heat sink and has an assemble surface and a second rough surface structure disposed on a portion of the assemble surface and corresponding to the first rough surface structure. The first and second rough surface structures and the supporting portions define a fluid chamber in which the elastic structure is disposed, and a working fluid flows in the fluid chamber.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan application serial no. 102143239, filed on Nov. 27, 2013. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a heat dissipation substrate, and more particularly, to a heat dissipation substrate adapted to carry at lest one heating element.

2. Description of Related Art

Generally, in order to enhance a heat dissipation effect of a vapor chamber, additional heat dissipation fins would usually disposed on the vapor chamber already fixed with a fluid chamber so as to form a so-called heat dissipation substrate. Since the overall thickness of the heat dissipation substrate is the sum of the thickness of the vapor chamber and the thicknesses of the heat dissipation fins, as compared to the thickness of a single vapor chamber, the thickness of the heat dissipation substrate is significantly increased by much, and thus is incompatible with the trend of slim and light.

SUMMARY OF THE INVENTION

The invention provides a heat dissipation substrate capable of solving the problem of causing a thicker overall thickness in the conventional heat dissipation substrate due to the addition of heat dissipation fins.

The heat dissipation substrate of the invention includes a heat sink, a metal base and at least one elastic structure. The heat sink includes a carrying portion and a plurality of supporting portions. The carrying portion has a carrying surface and a lower surface opposite to each other. The supporting portions are parallel to one another and disposed on the lower surface of the carrying portion. The supporting portions are perpendicular to the carrying portion and surround an accommodating space with the carrying portion. The carrying portion has a first rough surface structure disposed on a portion of the lower surface, and the first rough surface structure is located in the accommodating space. The metal base is disposed below the heat sink and has an assemble surface. The metal base has a second rough surface structure disposed on a portion of the assemble surface and corresponding to the first rough surface structure. The first rough surface structure, the second rough surface structure and the supporting portions define a fluid chamber, and a working fluid flows in the fluid chamber. The elastic structure is disposed within the fluid chamber.

In one embodiment of the invention, the heat dissipation substrate further includes a plurality of fixing elements disposed between the metal base and the supporting portions of the heat sink so as to fix the metal base on the heat sink.

In one embodiment of the invention, each of the supporting portions has a first supporting portion and a second supporting portion. The first supporting portion connects the lower surface of the heat sink and the second supporting portion. A thickness of the first supporting portion is greater than a thickness of the second supporting portion, the metal base is located in the accommodating space, and edges of the metal base contact the second supporting portion.

In one embodiment of the invention, each of the second supporting portions has a first threaded portion, a surrounding surface of the metal base has a second threaded portion, and the first threaded portion and the second threaded portion cooperatively fix the metal base on the supporting portions.

In one embodiment of the invention, the assemble surface of the metal base contacts an end of each of the supporting portions that is relatively far away from the carrying portion.

In one embodiment of the invention, the heat sink includes a plurality of heat dissipation fins arranged in parallel with each other. The heat dissipation fins are disposed on the supporting portions and located outside of the accommodating space.

In one embodiment of the invention, an extending direction of the heat dissipation fins is the same as an extending direction of the carrying portion.

In one embodiment of the invention, an extending direction of the heat dissipation fins is the same as an extending direction of the supporting portions.

In one embodiment of the invention, each of the heat dissipation fins has at least one heat dissipation hole, and an extending direction of each of the heat dissipation holes is perpendicular to an extending direction of each of the heat dissipation fins.

In one embodiment of the invention, the metal base further includes at lease one opening. The opening penetrates the metal base and connects with the fluid chamber.

In one embodiment of the invention, the first rough surface structure is a lumpy surface structure, and a Rymax of the first rough surface structure ranges from several micrometers to several centimeters.

In one embodiment of the invention, the second rough surface structure is a lumpy surface structure, and a Rymax of the second rough surface structure ranges from several micrometers to several centimeters.

In one embodiment of the invention, the working fluid includes air or liquid.

In one embodiment of the invention, the elastic structure is a spring.

In view of the foregoing, since the heat dissipation substrate of the invention is assembled with the heat sink, the metal base and the elastic structure, as compared to the overall thickness of a conventional heat dissipation substrate that has been disposed with additional heat dissipation fins on a vapor chamber already fixed with a fluid chamber, the heat dissipation substrate of the invention may have a thinner thickness and may flexibly adjust the space dimensions of the fluid chamber according to a location whereby the metal base is assembled to the heat sink, and thus a heat dissipation effect of the heat dissipation substrate may be enhanced. In addition, the elastic structure may also increase a total surface area and a structural strength within the fluid chamber.

Several exemplary embodiments accompanied with figures are described in detail below to further describe the disclosure in details.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments and, together with the description, serve to explain the principles of the disclosure.

FIG. 1 is a cross-sectional view schematically illustrating a heat dissipation substrate according to an embodiment of the invention.

FIG. 2 is a cross-sectional view schematically illustrating a heat dissipation substrate according to another embodiment of the invention.

FIG. 3 is a cross-sectional view schematically illustrating a heat dissipation substrate according to another embodiment of the invention.

FIG. 4 is a cross-sectional view schematically illustrating a heat dissipation substrate according to another embodiment of the invention.

FIG. 5 is a cross-sectional view schematically illustrating a heat dissipation substrate according to another embodiment of the invention.

FIG. 6 is a cross-sectional view schematically illustrating a heat dissipation substrate according to another embodiment of the invention.

DESCRIPTION OF EMBODIMENTS

FIG. 1 is a cross-sectional view schematically illustrating a heat dissipation substrate according to an embodiment of the invention. Referring to FIG. 1, in the present embodiment, a heat dissipation substrate 100 a includes a heat sink 110 a, a metal base 120 a and at least one elastic structure 140 (two are schematically illustrated in FIG. 1). The heat sink 110 a includes a carrying portion 112 a and a plurality of supporting portions 114 a. The carrying portion 112 a has a carrying surface S1 and a lower surface S2 opposite to each other. The supporting portions 114 a are parallel to one another and disposed on the lower surface S2 of the carrying portion 112 a. The supporting portions 114 a are perpendicular to the carrying portion 112 a and surround an accommodating space S with the carrying portion 112 a. The carrying portion 112 a has a first rough surface structure 116 a disposed on a portion of the lower surface S2, and the first rough surface structure 116 a is located in the accommodating space S. The metal base 120 a is disposed below the heat sink 110 a and has an assemble surface S3. The metal base 120 a has a second rough surface structure 126 a disposed on a portion of the assemble surface S3 and corresponding to the first rough surface structure 116 a. The first rough surface structure 116 a, the second rough surface structure 126 a and the supporting portions 114 a define a fluid chamber C1, and a working fluid F flows in the fluid chamber C1, and the elastic structures 140 are disposed within the fluid chamber C.

More specifically, each of the supporting portions 114 a of the heat sink 110 a of the present embodiment has a first supporting portion 114 a 1 and a second supporting portion 114 a 2. The first supporting portion 114 a 1 connects the lower surface S2 of the heat sink 110 a and the second supporting portion 114 a 2. A thickness of the first supporting portion 114 a 1 is greater than a thickness of the second supporting portion 114 a 2. The lower surface S2 of the carrying portion 112 a surrounds the accommodating space S with the supporting portions 114 a. On the other hand, the first rough surface structure 116 a, the second rough surface structure 126 a and the second supporting portions 114 a 2 of the supporting portions 114 a define the fluid chamber C1. Moreover, the heat sink 110 a of the present embodiment further includes a plurality of heat dissipation fins 118 a, wherein the heat dissipation fins 118 a are arranged in parallel with each other, and the heat dissipation fins 118 a are disposed on the supporting portions 114 a and outside of the accommodating space S. As shown in FIG. 1, the heat dissipation fins 118 a are located on the supporting portions 114 a, and an extending direction of the heat dissipation fins 118 a is substantially the same as an extending direction of the carrying portion 112 a; namely, the extending direction of the heat dissipation fins 118 a is perpendicular to an extending direction of the supporting portions 114 a. Cross-sectional areas of the heat dissipation fins 118 a gradually decrease from near the supporting portions 114 a towards a direction far away from the supporting portions 118 a, but not limited thereto. Herein, the carrying portion 112 a, the supporting portions 114 a and the heat dissipation fins 118 a of the heat sink 110 a of the present embodiment are seamlessly connected with each other, namely, integrally formed, but not limited thereto.

In the present embodiment, a material of the metal base 120 a is selected from copper, aluminum or an alloy of the above, wherein the metal base 120 a is located in the accommodating space S, and edges of the metal base 120 a contact the second supporting portion 114 a 2 of the supporting portions 114 a. Since the metal base 120 a is located in the accommodating space S, the space dimensions of the accommodating space S of the present embodiment is substantially greater than the space dimensions of the fluid chamber C1. Furthermore, the elastic structure 140 of the present embodiment is substantially a spring, which can effectively increases a total surface area and a structural strength of the fluid chamber C1. In addition, in order to enhance an assembly reliability, the heat dissipation substrate 100 a of the present embodiment may further include a plurality of fixing elements 130, wherein the fixing elements 130 are disposed between the metal base 120 a and the supporting portions 114 a of the heat sink 110 a, so as to fix the metal base 120 a on the heat sink 110 a. Herein, the fixing elements 130, for example, are screws, nuts, rivets or leak stopping elements having both a fixing function and an airtight and watertight function, but not limited thereto; structure designs achieving the same level of fixing effect are all within the protection scope of the invention. In brief, the heat dissipation substrate 100 a of the present embodiment is assembled from the heat sink 110 a and the metal base 120 a with the fixing elements 130.

Furthermore, the metal base 120 a of the present embodiment may further have at least one opening H, wherein the opening H penetrates the metal base 120 a and connects with the fluid chamber C1, so as to extract air from or to inject fluid to the fluid chamber C1 via the opening H, thereby enhancing an heat dissipation efficiency of the overall heat dissipation substrate 100 a. Herein, the opening H is able to be inserted with a metal tubule (not shown) for exhausting air or injecting fluid, so that the fluid chamber C1 enters a low vacuum state, and afterwards, the inserted metal tubule is sealed. Herein, the fluid chamber C1 is substantially as a low vacuum chamber, and the working fluid F, for example, is air or liquid.

Particularly, the first rough surface structure 116 a of the carrying portion 112 a of the heat sink 110 a of the present embodiment, for example, is a continuous lumpy surface structure or a discontinuous lumpy surface structure, and a Rymax of the first rough surface structure 116 a ranges from several micrometers to several centimeters. The first rough surface structure 116 a may be considered as a type of capillary structure. On the other hand, the second rough surface structure 126 a of the metal base 120 of the present embodiment, for example, is a continuous discontinuous lumpy surface structure or a discontinuous lumpy surface structure, and a Rymax of the second rough surface structure 132 ranges from several micrometers to several centimeters. The second rough surface structure 126 a may be considered as a type of capillary structure. Herein, the first rough surface structure 116 a and the second rough surface structure 126 a, for example, are processed via machining, such as computer numerical control (CNC) milling technique, stamping or sandblasting; or chemical processing, such as electroplating or etching; or physical grinding, but not limited thereto.

Since the heat dissipation substrate 100 a of the present embodiment is substantially assembled from the heat sink 110 a and the metal base 120 a with the fixing elements 130, as compared to the overall thickness of a conventional heat dissipation substrate that has been disposed with additional heat dissipation fins on a vapor chamber already fixed with a fluid chamber, the heat dissipation substrate 100 a of the present embodiment may have a thinner thickness and may flexibly adjust the space dimensions of the fluid chamber C1 according to the location whereby the metal base 120 a is assembled to the heat sink 110 a, and thus a heat dissipation effect of the heat dissipation substrate 100 a may be enhanced. In addition, the heat dissipation substrate 100 a of the present embodiment may increase a total surface area and a structural strength within the fluid chamber C1 through the design of the elastic structures 140.

When a heating element (not shown) is disposed on the carrying surface S1 of the carrying portion 112 a, the working fluid F with in the fluid chamber C1 absorbs energy E generated by the heating element and is vaporized in a low vacuum environment. Now, the working fluid F absorbs the energy E and rapidly expends in volume, and the vaporized working fluid F soon fills up the entire fluid chamber C1. A phenomenon of condensation is generated when the vaporized working fluid F encounters regions with lower temperature, so that the energy E being absorbed during the vaporization is released through the phenomenon of condensation. The condensed liquid working fluid F is returned to the evaporation location (viz. below the heating element) through capillary actions of the first rough surface structure 116 a and the second rough surface structure 126 a. As such, i.e., through repeating cycling steps of conduction, evaporation, convection and condensation, the energy E generated by the heating element may quickly be transferred to each part of the heat dissipation substrate 100 a. In brief, the heat dissipation substrate 100 a of the present embodiment may be considered as a vapor chamber having a favorable flat-plate structure with two-phase flow characteristics and may provide an excellent two-dimensional transverse heat conduction effect for quickly diffusing the energy E generated by the heating element, thereby avoiding formations of hot spots at partial regions and prolonging the serve-life of the heating element.

Several embodiments are provide in the following below for describing the structure designs of heat dissipation substrate 100 b, 100 c and 100 d in details. It is to be explained that, the following embodiments have adopted component notations and part of the contents from the previous embodiment, wherein the same notations are used for representing the same or similar components, and descriptions of the same technical contents are omitted. The descriptions regarding to the omitted part may be referred to the previous embodiments, and thus is not repeated herein.

FIG. 2 is a cross-sectional view schematically illustrating a heat dissipation substrate according to another embodiment of the invention. Referring to FIG. 2, the heat dissipation substrate 100 b of the present embodiment is similar to the heat dissipation substrate 100 a of FIG. 1, except that a main difference between the two lies in: an extending direction of heat dissipation fins 118 b of a heat sink 110 b of the present embodiment is the same as the extending direction of the supporting portions 114 a, namely, the extending direction of the heat dissipation fins 118 b is perpendicular to the extending direction of the carrying portion 112 a. As shown in FIG. 2, the heat dissipation fins 118 b of the present embodiment substantially are located on the lower surface S2 of the carrying portion 112 a not being disposed with the first rough surface structure 116 a, and cross-sectional areas of the heat dissipation fins 118 b gradually decrease from near the lower surface S2 of the carrying portion 112 a towards a direction far away from the lower surface S2 of the carrying portion 112 a, but not limited thereto.

FIG. 3 is a cross-sectional view schematically illustrating a heat dissipation substrate according to another embodiment of the invention. Referring to FIG. 3, the heat dissipation substrate 100 c of the present embodiment is similar to the heat dissipation substrate 100 a of FIG. 1, except that a main difference between the two lies in: the space dimensions of a fluid chamber C2 are greater than the space dimensions of the fluid chamber C1 of FIG. 1. In detail, an assemble surface S3′ of a metal base 120 c of the present embodiment contacts an end of each of the supporting portions 114 c of the heat sink 110 a that is far away from the carrying portion 112 a. Now, the space dimensions of the fluid chamber C2 are roughly equal to the accommodating space S. Herein, as shown in FIG. 3, the supporting portions 114 c of the present embodiment have a same thickness.

FIG. 4 is a cross-sectional view schematically illustrating a heat dissipation substrate according to another embodiment of the invention. Referring to FIG. 4, the heat dissipation substrate 100 d of the present embodiment is similar to the heat dissipation substrate 100 c of FIG. 3, except that a main difference between the two lies in: an extending direction of heat dissipation fins 118 d of a heat sink 110 d of the present embodiment is the same as the extending direction of the supporting portions 114 c, namely, the extending direction of the heat dissipation fins 118 d is perpendicular to extending direction of the carrying portion 112 a. As shown in FIG. 4, the heat dissipation fins 118 d of the present embodiment substantially are located on the lower surface S2 of the carrying portion 112 a not being disposed with the first rough surface structure 116 a, and cross-sectional areas of the heat dissipation fins 118 d gradually decrease from near the lower surface S2 of the carrying portion 112 a towards the direction far away from the lower surface S2 of the carrying portion 112 a, but not limited thereto.

FIG. 5 is a cross-sectional view schematically illustrating a heat dissipation substrate according to another embodiment of the invention. Referring to FIG. 5, the heat dissipation substrate 100 e of the present embodiment is similar to the heat dissipation substrate 100 a of FIG. 1, except that a main difference between the two lies in: each of a plurality of second supporting portions 114 d 2 of supporting portions 114 d of the present embodiment has a first threaded portion 115, a surrounding surface 121 of a metal base 120 e has a second threaded portion 123, and the first threaded portion 115 and the second threaded portion 123 cooperatively fix the metal base 120 e on the supporting portions 114 d. Namely, the metal base 120 e may be fixed on any position on the second supporting, portion 114 d 2 via the cooperation between the second threaded portion 123 and the first threaded portion 115, but it is not limited to that the metal base 120 e must be in contact with a first supporting portion 114 d 1. Furthermore, each of a plurality of heat dissipation fins 118 e of a heat sink 110 e of the present embodiment may further include at least one heat dissipation hole 119 e, and an extending direction of each of the heat dissipation holes 119 e is perpendicular to an extending direction of each of the heat dissipation fins 118 e, so that a heat dissipation effect of the heat dissipation substrate 100 e may be enhanced. In addition, a fixing element 130 f of the present embodiment substantially is a leak stopping element having both a fixing function and an airtight and watertight function, so that the a reliability of the fluid chamber C1 may be enhanced.

FIG. 6 is a cross-sectional view schematically illustrating a heat dissipation substrate according to another embodiment of the invention. Referring to FIG. 6, the heat dissipation substrate 100 f of the present embodiment is similar to the heat dissipation substrate 100 d of FIG. 4, except that a main difference between the two lies in: each of a plurality of heat dissipation fins 118 f of a heat sink 110 f of the present embodiment may further include at least one heat dissipation hole 119 f, and an extending direction of each of the heat dissipation holes 119 f is perpendicular to an extending direction of each of the heat dissipation fins 118 f, so that a heat dissipation effect of the heat dissipation substrate 100 f may be enhanced.

In summary, since the heat dissipation substrate of the invention is assembled with the heat sink and the metal base, as compared to the overall thickness of the conventional heat dissipation substrate that has been disposed with additional heat dissipation fins on the vapor chamber already fixed with the fluid chamber, the heat dissipation substrate of the invention may have the thinner thickness and may flexibly adjust the space dimensions of the fluid chamber according to the location whereby the metal base is assembled to the heat sink, and thus the heat dissipation effect of the heat dissipation substrate may be enhanced. In addition, the elastic structure may also increase the total surface area and the structural strength within the fluid chamber.

It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims and their equivalents. 

What is claimed is:
 1. A heat dissipation substrate, comprising: a heat sink comprising a carrying portion and a plurality of supporting portions, the carrying portion having a carrying surface and a lower surface opposite to each other, the supporting portions being parallel to one another and disposed on the lower surface of the carrying portion, wherein the supporting portions are perpendicular to the carrying portion and surround an accommodating space with the carrying portion, the carrying portion has a first rough surface structure disposed on a portion of the lower surface, and the first rough surface structure is located in the accommodating space; a metal base disposed below the heat sink and having an assemble surface, wherein the metal base has a second rough surface structure disposed on a portion of the assemble surface and corresponding to the first rough surface structure, the first rough surface structure, the second rough surface structure and the supporting portions define a fluid chamber, and a working fluid flows in the fluid chamber; and at least one elastic structure disposed within the fluid chamber.
 2. The heat dissipation substrate as recited in claim 1, further comprising: a plurality of fixing elements disposed between the metal base and the supporting portions of the heat sink so as to fix the metal base on the heat sink.
 3. The heat dissipation substrate as recited in claim 1, wherein each of the supporting portions has a first supporting portion and a second supporting portion, the first supporting portion connects the lower surface of the heat sink and the second supporting portion, a thickness of the first supporting portion is greater than a thickness of the second supporting portion, the metal base is located in the accommodating space, and edges of the metal base contact the second supporting portions.
 4. The heat dissipation substrate as recited in claim 3, wherein each of the second supporting portions has a first threaded portion, a surrounding surface of the metal base has a second threaded portion, and the first threaded portions and the second threaded portion cooperatively fix the metal base on the supporting portions.
 5. The heat dissipation substrate as recited in claim 1, wherein the assemble surface of the metal base contacts an end of each of the supporting portions that is relatively far away from the carrying portion.
 6. The heat dissipation substrate as recited in claim 1, wherein the heat sink further comprises a plurality of heat dissipation fins arranged in parallel with each other, and the heat dissipation fins are disposed on the supporting portions and located outside of the accommodating space.
 7. The heat dissipation substrate as recited in claim 6, wherein an extending direction of the heat dissipation fins is the same as an extending direction of the carrying portion.
 8. The heat dissipation substrate as recited in claim 6, wherein an extending direction of the heat dissipation fins is the same as an extending direction of the supporting portions.
 9. The heat dissipation substrate as recited in claim 6, wherein each of the heat dissipation fins has at least one heat dissipation hole, and an extending direction of each of the heat dissipation holes is perpendicular to an extending direction of each of the heat dissipation fins.
 10. The heat dissipation substrate as recited in claim 1, wherein the metal base further comprises at least one opening, and the opening penetrates the metal base and connects with the fluid chamber.
 11. The heat dissipation substrate as recited in claim 1, wherein the first rough surface structure is a lumpy surface structure, and a Rymax of the first rough surface structure ranges from several micrometers to several centimeters.
 12. The heat dissipation substrate as recited in claim 1, wherein the second rough surface structure is a lumpy surface structure, and a Rymax of the second rough surface structure ranges from several micrometers to several centimeters.
 13. The heat dissipation substrate as recited in claim 1, wherein the working fluid comprises air or liquid.
 14. The heat dissipation substrate as recited in claim 1, wherein the elastic structure is a spring. 